The recognition of the contract of sale is rightly said to be a key achievement of the Roman jurists. In Roman law, it had three characteristics. First, a sale is entered into informally. The parties are bound without the use of any special formality such as an oath, a document, a deed, or even a handshake. Second, sale is what the Romans called a contract of good faith (bonae fidei) as distinguished from a contract of strict law (stricti iuris). The parties are bound, not only to what they said, but to all the obligations that follow as a matter of good faith. Third, a sale is binding upon consent before delivery of the goods to be sold or payment of any of the purchase price. Virtually all modern legal systems recognize a contract of sale with these three features. The Romans were the first.. . .